Weapons system modification for improved piston system

ABSTRACT

This invention is directed to a rifle barrel sleeve system for a piston operated weapon system comprising: a rear sleeve surrounding a rear portion of the rifle barrel; a front sleeve surrounding a front portion of the rifle barrel; a gas elbow support surrounding the rifle barrel disposed between the rear sleeve and the front sleeve having a gas chamber allowing gas to escape from a barrel gas port into the gas elbow; and, a void defined between the rear sleeve, front sleeve, gas elbow, barrel having filler material, a cylinder attached to a chamber bushing, sizing member and piston and rod.

FIELD OF THE INVENTION

This invention is directed to a weapons system having a rifle, shotgun or cannon barrel and more particularly to a piston operated weapon system and a conversion kit for converting a gas operated system to a piston operated system.

This invention is directed to the construction and/or modification of a rifle, shotgun or cannon barrel providing a sandwich barrel design for reducing heat and harmonics, removing the effect of piston impingement and for improving accuracy. The improved piston system can be combined with a modified gun barrel to reduce flex and harmonics while providing for reduced impingement with the improved piston system. The present invention can be of new construction or can be used to convert an existing gas operated weapon system to an improved piston operated weapon system.

BACKGROUND

It has been long understood that a rifle's barrel changes shape and moves in multiple directions every time the rifle is fired. This effect is also found in shotgun and cannon barrels. In some instances, this movement of the barrel has been coined “barrel whip” and is when a weighted object (bullet) travels down the tubular barrel under intense gas pressure generally defined as when the barrel is away from its “static” state. Barrel whip can occur when the bullet accelerates into a rapid spin, when the stock drops significantly so the muzzle rises when the rifle is fired, or when a pressure wave travels the length of the barrel. In the case of shotguns and unrifled cannon barrels, the “barrel whip” largely results from the pressure wave traveling along the barrel.

Barrel whip reduces the accuracy of the projectile expelled from the barrel and, therefore, the ability of a shooter to hit a target. Historically, manufacturers of barrels have simply accepted that the barrel's movement can't be eliminated. The remedy was to manufacture the barrel so that at least the movement was consistent with each shot. With a combination of cartridge loads and a consistently moving barrel whip, a rifle can be made more accurate by matching the load with the barrel. However, this requires that cartridge loads be customized to match each individual barrel and requires a high degree of customization.

Further, with each shot, the chamber can swell and produce an annular wave that travels between the muzzle and the breech. As the annular wave travels down the barrel, the bore diameter changes slightly as a result of the wave. If the bullet exits the barrel coincidentally with the wave at the muzzle, the bullet accuracy is greatly reduced since the bore and the bullet will be ejected through a bore that is made larger due to the wave. Traditional attempts to avoid this problem have been to change the cartridge load so that the bullet does not exit the barrel when the annular wave is at the muzzle. Again, this involves a high degree of customization and requires that cartridge loads match each individual barrel.

Further, as rounds are shot through a barrel, the barrel heats and the metal expands, becomes more flexible, and, therefore, the effect of barrel whip and any annular waves increases. Some tests have found that the center of the bore can change as much as 0.001 inches between the barrel temperatures of 77° F. (ambient) and 122° F. While the number of rounds that it takes to heat a barrel from ambient to over 120° F. varies greatly with the type of round, the type of barrel and other factors, such temperature changes can occur in as little as four or five rounds. Therefore, for multiple shots, the heat generated by the shots can adversely affect the accuracy of the barrel.

An additional problem arises in weapon systems that utilize gas return mechanisms to capture escaping gas from the barrel and redirect the gas into the action to cycle the bolt for filing the next round. Typically, a rifle with a gas management system, such as an AR15/M4 platform which includes a gas exit port disposed along the length of the barrel, and in some cases, is part of the front sight assembly. A metal tube is connected to the port and runs back along the length of the barrel and into the action of the rifle. As a bullet is fired down the barrel, gas is forced into the tube and then into the action to help cycle the bolt to fire the next round. In current designs, however, the gas return tube is free floating along the length of the barrel and only secured at its distal ends. A problem arises in that when gas is forced into the tube, it can cause the tube to flex and create additional harmonics that interact with the barrel whip described above. Thus, an additional loss of accuracy is suffered in these weapon systems.

Attempts to improve the accuracy and reliability is to use a piston system rather than a gas operated system as shown in United States Patent Application Publication 2012/0152104. However, the cylinder that receives the piston is disposed along the barrel and is not carried by a sleeve that surrounds the barrel. The design results in more physical movement of the barrel and the hand guard and ultimately results in a less accurate weapon system. Further, the hand guard is particular to this design and this design cannot be retro fitted to an existing weapon system without replacement of the hand guard. When the piston is actuated, the force of the impingement causes the barrel to move thereby reducing accuracy.

U.S. Pat. No. 8,201,489 is a piston system with the piston housing attached to the trunnion and not the sleeve that surrounds the barrel. Again, this design places unnecessary force on the trunnion which can cause the weapon system to be inaccurate.

Accordingly, it is an object of the present invention to provide a piston operated weapons system to reduce the effects of impingement thereby reducing barrel whip.

It is a further object of the present invention to provide a conversion system for converting a gas operated system to a piston system.

It is a further object of the present invention to provide for a piston weapon system with a cylinder attached to a sleeve surrounding the barrel defining a void having filler material to improve accurate of the weapon system.

SUMMARY OF THE INVENTION

The present invention is accomplished by providing A weapon system including a barrel, a gas escape opening defined in the barrel, a receiver and a gas tube opening defined in the receiver comprising: a front sleeve surrounding a front portion of the rifle barrel; a rear sleeve surrounding a rear portion of the rifle barrel; a gas elbow support surrounding the rifle barrel disposed between the front sleeve and the rear sleeve wherein the gas elbow redirects gas escaping from the gas escape opening; a cylinder attached to the rear sleeve; a gas tube connected between the gas elbow and the cylinder directing gas from the gas elbow to the cylinder; a piston slidably received in the cylinder so that when gas from the gas tube is directed into the cylinder, the piston moves toward the receiver; and, a rod slidably received in the cylinder and the gas opening in the receiver so that when the piston moves toward the receiver, the rod extends into the receiver and contacts a contact member of a bolt causing the bolt to cycle.

The invention can include a void defined between the front sleeve, gas elbow, rear sleeve and the outer surface of the barrel; and, a filler material disposed in the void. The filler material can include material taken from the group consisting of: hydraulic cement, at least 50% by weight of calcium sulfate, 48% of less by weight of portland cement, epoxy, resin, graphite and metal particles.

An adjustment screw can be included in the gas elbow to adjust the amount of gas received in the gas tube from the gas elbow thereby varying the force placed on the piston by the directed gas. A sizing member can be included in the cylinder that receives the gas tube to reduce the amount of gas escaping from around the gas tube. A chamber bushing can be carried by the receiver and attached to the rear sleeve and cylinder. A cylinder exhaust port can be included allowing gas directed into the cylinder to exit the cylinder once the piston travels a predetermined distance to prevent overpressure in the cylinder. The rod, received in the gas tube opening and the cylinder, can have 25% or less if the rod is exposed outside the cylinder or receiver to reduce the rod flexing during operation. Flow channels can be present to provide for fluid communications between the rear void, gas elbow and front void.

DESCRIPTION OF THE DRAWINGS

The construction designed to carry out the invention will be described, together with other features thereof. The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown and wherein:

FIG. 1A is a side view of the prior art;

FIGS. 1B and 1C are perspective views of the prior art;

FIG. 1D is a perspective view of the invention;

FIG. 1E is a perspective view of the prior art;

FIG. 1F is a muzzle view of the prior art;

FIGS. 2A through 2F are schematics illustrating the need for the invention;

FIGS. 3A and 3B are schematics illustrating the need and results of the invention;

FIG. 4 is a chart illustrating heat building in a barrel;

FIGS. 5A and 5B are schematics of the invention;

FIGS. 6A through 6E are schematics of the invention;

FIG. 7 is a flowchart illustrating the invention;

FIG. 8 is a cross section of aspects of the invention;

FIGS. 9A through 9C illustrate the prior art;

FIG. 10 illustrates aspects of the invention;

FIG. 11A is an exploded view of components of the invention;

FIG. 11B is an assembled view of components of the invention;

FIG. 12 is a cross-sectional view of a component of the invention;

FIG. 13 is a perspective view of aspects of the invention;

FIGS. 14A and 14B are perspective views of aspects of the invention;

FIG. 15 is a perspective view of aspects of the invention;

FIG. 16A is a perspective view of an aspect of the invention; and,

FIG. 16B is an elevated view of an aspect of the invention.

It will be understood by those skilled in the art that one or more aspects of this invention can meet certain objectives, while one or more other aspects can meet certain other objectives. Each objective may not apply equally, in all its respects, to every aspect of this invention. As such, the preceding objects can be viewed in the alternative with respect to any one aspect of this invention. These and other objects and features of the invention will become more fully apparent when the following detailed description is read in conjunction with the accompanying figures and examples. However, it is to be understood that both the foregoing summary of the invention and the following detailed description are of a preferred embodiment and not restrictive of the invention or other alternate embodiments of the invention. In particular, while the invention is described herein with reference to a number of specific embodiments, it will be appreciated that the description is illustrative of the invention and is not constructed as limiting of the invention. Various modifications and applications may occur to those who are skilled in the art, without departing from the spirit and the scope of the invention, as described by the appended claims. Likewise, other objects, features, benefits and advantages of the present invention will be apparent from the summary and certain embodiments described below, and will be readily apparent to those skilled in the art. Such objects, features, benefits and advantages will be apparent from the above in conjunction with the accompanying examples, data, figures and all reasonable inferences to be drawn there from, alone or with consideration of any references incorporated herein.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1A through 1F, a barrel 10 is shown attached to a gas operated reloading weapon. For example, the AR15 or M4 model rifle is a popular gas operated weapon system. Generally, such weapon systems include a barrel 10 having a receiver 12 and muzzle 14. Round 18 a (FIG. 1E), which may be a shotgun shell containing multiple shot or a single slug projectile cartridge round, is received by a barrel 10. Rounds can be inserted either individually into the breech or through a magazine configuration 20 for holding multiple rounds as is well known to those skilled in the art. In the magazine configuration, the rounds are biased in a direction such as shown by 22 so that when the action of the rifle or shotgun is cycled, rounds are inserted into the breech and can be filed. The barrel defines a bore 24 (FIG. 1B). The bore can be a smooth bore, such as in a shotgun or cannon, or contain rifling as is common in most rifles and smaller single projectile fire arms such as handguns.

In some existing gas operated systems, a gas tube 11 is included in the gas operated weapon system. The gas tube receives gas that travels the barrel down the bore, out the gas port in and toward the action where it is expelled to assist the bolt to be pushed backward to cycle the next round in the magazine. Traditionally in a gas operated or gas assisted action the system utilizes gas from the expended cartridge to assist the operation of and the complete cycling of the bolt. Gas block 13 (FIG. 1C) is placed around the barrel so that an opening defined in the gas block aligns with an opening in the barrel to allow escaping gas to enter the gas block. The gas tube is received by the opening in the gas block and allows the escaping gas to be directed rearward to the action.

Referring to FIG. 1D, the barrel 10 can include an inner barrel and a front sleeve 166 surrounding a front portion of the barrel, a gas elbow 160 and a rear sleeve 154 surrounding a rear portion of the barrel. The gas elbow can surround the barrel and be disposed between the front and rear sleeve. A void is can be defined by the space between the inner wall of the front sleeve, gas elbow and rear sleeve and the outer wall of the barrel. A chamber bushing 158 can be included for receiving the rear sleeve and attached to the inner barrel. A cylinder 200 can be affixed at a chamber area 202 to the chamber bushing or to the rear sleeve. A gas tube 23 can be included that is received in the gas elbow and into the cylinder providing fluid communication between the gas elbow and the cylinder. A sizing member 204 can be received in the cylinder effectively sealing the cylinder so that gas from the gas tube is directed into the cylinder and the amount of gas that escapes around the gas tube is reduced or eliminated. The sizing member can include an opening for receiving the gas tube allowing gas to travel from the gas tube to the sizing member. A piston 206 is disposed in the cylinder and moves in direction 210 when gas is directed into the cylinder. The piston then contacts rod 212 which extends out of the cylinder, into the receiver and comes in contact with the bolt thereby cycling the bolt. A cylinder exhaust port 214 can be included in the cylinder to allow unused gas to be expelled out the port. This reduces or prevents gas from entering the action of the weapon system. When the piston or rod travels a predetermined distance and extends in the cylinder rearward a sufficient length to pass the exhaust port, gas is expelled out the exhaust port to prevent over pressure. An adjustment screw 216 can be included to allow adjustment of the amount of gas that is directed from the barrel to the gas tube.

The sizing member can be secured to the cylinder by pin 155 a that can be received in opening 155 b defined in the cylinder. An opening in the sizing member 155 c can be received in 155 b. The gas tube can be secured to the elbow with pin 157 a that is received in an opening in the elbow 157 b. Pin 157 a can be received in an opening 157 c in the end of the gas tube to secure the gas tube to the elbow (gas block).

Referring to FIGS. 2A through 2E, a cartridge (or shotgun shell/round) 26 is shown having case 28 and bullet 30. In the case of a shotgun, bullet 30 may be a single projectile (slug) or a plurality of small projectiles commonly referred to as shot. The construction of shotgun shells is well known to those skilled in the art and thus not specifically illustrated. It should be understood by those of ordinary skill in the art that the present invention is applicable to any and all weapons systems utilizing a barrel to eject a projectile(s) regardless of the form of the round or number of projectiles contained in a single cartridge. Case 28 can contain gunpowder or other explosives that when ignited, expands and pushes the bullet through the bore. In the case where the bore contains rifling, the bullet is caused to rotate in a direction illustrated as 32 which causes the bullet to spin within and upon leaving the bore. When the bullet is pushed out the bore, torque is applied to the barrel and the barrel can experience barrel whip shown as 34. As previously explained, barrel whip adversely impacts the accuracy of the barrel as the bullet can leave the muzzle when the bore is “off target.” It should be noted that the barrel whip can be in a linear direction or circular so that the barrel can whip in two or three dimensions.

Referring to FIG. 2D, the expanding gas from the ignited explosive can create an annular wave 36 that initially travels in a direction 38 down the barrel and will rebound in a direction opposite 38 and “bounce” back and forth for some period of time along the barrel. When the annular wave reaches the muzzle, the muzzle of the barrel can “whip” so that the bore moves “off target”. This effect is particularly undesirable when bullet 30 and annular wave 38 reach the muzzle approximately contemporaneously. The barrel whip effect is equally undesirable in smooth bore barrel weapons such as shotguns and cannons.

Referring to FIG. 2F, when the annular wave travels down a barrel containing a traditional gas block, the annular wave can further vibrate the barrel as the gas block is effected by the same. Further, the annular wave can be magnified if the forces exerted on the gas tube from the operation of the action are imparted to the barrel at point 17 due to the physical contact and force being transferred from the gas tube to the gas block to the barrel. When multiple rounds are fired and the barrel temperature rises as shown in FIG. 4, the “barrel whip” is magnified.

Given the multiple undesirable forces on the barrel, the accuracy of any rifle, shotgun or cannon is significantly compromised, particularly after multiple rounds are fired in relatively quick succession. Referring to FIGS. 3A and 3B, the results of a rifle barrel that has not been modified or manufactured with the present invention is illustrated as 40. Once the invention was applied to the above rifle barrels, the results are illustrated as 42 showing a significant improvement in accuracy.

Referring to FIGS. 5A and 5B, a barrel nut 90 can be modified to include a sleeve receiving area 92 having an inner diameter greater than that of an unmodified barrel nut. The receiving area then receives the sleeve so that at least a portion of the sleeve is disposed inside the barrel nut as shown in FIG. 5B.

The sleeve and the outer boundary of the barrel define a void between the sleeves and the inner barrel. In one embodiment the sleeve is manufactured from stainless steel. The sleeve can also be manufactured from other metals, composite plastics, or a fibrous material sufficient to maintain its structure while being exposed to the heat and vibrations of a weapon system barrel. The sleeve can be generally circular or polygonic in shape.

In one embodiment, the sleeve is generally twice the diameter of the rifle, shotgun or cannon barrel. In one embodiment, the barrel is machined to reduce the diameter of the barrel prior to installing the sleeve. This allows for the use of a smaller diameter sleeve and can assist with replacement of the modified barrel back in the stock of the rifle or other component of the weapons system. It should be noted that the sleeve need not be circular in shape and can be any shape including hexagon, oval, square and such.

In some configurations, it may be necessary to apply a sealant such as epoxy or putty at the sleeve breech opening so as to generate a seal between the sleeve and the barrel. Once the sleeve is in place, the barrel and sleeve are placed in a vertical position, in one embodiment as shown in FIGS. 6A through 6E. A barrel centering member 52 is used to center the barrel in the sleeve. In one embodiment, the barrel centering member 52 contains a distal member 54 that is received in bore 24. Spacing members 56 a through 56 c carried by spacing member 52 positions the barrel generally parallel to the center axis of the sleeve wherein the center axis of the sleeve coincides with the center axis of the barrel. It should be noted that placement of the barrel in the sleeve need not be exact to achieve the benefits of this invention.

In one embodiment, a realignment tool 84 is used to align the barrel in the sleeve. In this embodiment, the muzzle end 86 is placed in the bore of the barrel. The end cap or threads are placed on the muzzle end generally at 88 so that when the alignment tool is placed in the bore, the end cap or threads can be aligned with the sleeve. A muzzle brake can be placed generally at 90 over the alignment tool and attached to the end cap so that the threads, muzzle brake and alignment tool are carried within the muzzle brake and tool, so that when the alignment tool is inserted into the bore, the barrel can be aligned within the sleeve, and the sleeve can be aligned with the tool and muzzle brake.

Once the sleeve is in place and the barrel is positioned with the sleeve, filler material 58 is placed in void 50 defined by the sleeve and the barrel. In the case of double barrel shotguns, the sleeve is constructed and arranged to enclose both barrels and the filler material 58 is then simultaneously placed in the void surrounding both barrels in the same manner as described above for a single barrel. The filler material can be applied in a semi-fluid state and poured between the sleeve and the barrel.

In one embodiment the filler material is hydraulic cement, a hydraulic cement comprising at least 50% calcium sulfate and 48% or less portland cement and may contain amorphous silica, alumina, limestone dust, clay, quartz, calcium hydroxide and calcium sulfo aluminate. In one embodiment the filler material is hydraulic cement comprising at least 90% calcium sulfate and 10% or less portland cement. The filler material can also be epoxy or resins that are able to withstand the heat generated from the firing of a barrel of a weapons system. In one embodiment, the filler material is mixed with metal to enhance the filler materials' ability to absorb and quickly dissipate heat from the barrel. In one embodiment, the metal is in the form of metal shavings. In one embodiment, the metal is in the form of a ellipsoid or sphere. In one embodiment, the metal is in particles with irregular shapes.

In one embodiment, a muzzle brake 60 can be installed after the sleeve and filler material have been installed. In one embodiment, an end cap 61 can be attached to the muzzle end of the sleeve. This end cap can be simply an end cap defining a center opening that is the same diameter of the bore of the barrel. The opening of the end cap can also be slightly larger than the barrel diameter. In one embodiment, the end cap has a threaded portion 65 that can receive a corresponding threaded portion (not shown) of a muzzle brake, or other attachment to attach the muzzle brake of the other attachment to the threaded end cap which allows for its attachment and removal without having to attach or remove the end cap.

Referring to FIG. 7, the method of practicing this invention will be explained in more detail. The next step is to dissemble the weapon system and remove the barrel and gas tube at 62. The barrel can be de-greased and painted at 64. If the barrel diameter needs to be reduced at 66, the barrel is reduced at 68. In one embodiment, the barrel exterior surface is roughed to promote a more cohesive bond between the filler material and the barrel. Such roughing can be accomplished through the use of abrasive means such as sandpaper. The barrel can be re-crowned at 70. The barrel can also be painted at 70. In one embodiment, circumferential grooves, such as shown in FIG. 8, are cut into the barrel to provide larger void between the sleeve and the barrel for receiving filler material at 71. The gas return assembly is installed at 72.

The sleeve is measured and cut to the appropriate length based upon the barrel being modified. In one embodiment, the action end of the sleeve is beveled and squared so that it fits square against the action end of the barrel. A sleeve is placed over the barrel at 73. In one embodiment, the sleeve is pressed against the barrel using a press. If there is a gap between the sleeve breech opening and the barrel as determined at 74, the gap should be closed at 76. The action of the weapons system is locked and the muzzle centering device is installed at 78. The bore of the barrel is plugged and filler material is placed in the void defined by the barrel and the sleeve at 80 and the filler material is allowed to cure. In one embodiment, the twelve inches or so at the muzzle end of the sleeve is heated prior to the filler material curing. The external fittings are replaced at 82 which can include tightening the muzzle brake to ensure proper clocking (alignment), welding on the end cap, threads or muzzle brake. In one embodiment, clamps are used to secure the end cap, threads, or muzzle brake to the sleeve to assist with proper attachment when welding. The sleeve and some of the exposed portion of the barrel can be finished through painting, polishing, etc. The end cap, threads or muzzle brake, if used, have the center opening drilled to ensure that there is no grazing when a bullet leaves the muzzle of the rifle barrel. The sleeve can be marked for maximum caliber and the muzzle brake can be marked for the specific chambering of the rifle.

Referring to FIG. 8, a cross-section of the invention is shown. Barrel 10 can be milled or otherwise modified to include one or more grooves shown as 100 a through 100 d. These grooves, when included, define void 50. When the filler material is placed in void 50, the filler material is received by the grooves and results in the filler material more securely affixing to the barrel.

In one embodiment, the barrel includes original threads 102 which can be used to attach muzzle brake, suppresser or other accessories to the original barrel of the weapon system. When the barrel is received by sleeve 44, the original thread can be completely covered by the sleeve or can protrude from the muzzle end of the sleeve. An end cap 104 can be attached to the sleeve to further define void 50. The end cap can include end cap threads 106 for attaching a muzzle brake, suppressor or other accessories. The end cap can cover the void at the muzzle end shown at 108 to prevent muzzle gases from entering the void area and interfering with or otherwise effecting the filler material. The end cap can be permanently affixed to the sleeve through welding or the like at point 110.

In one embodiment, the barrel can be milled down to reduce its diameter thereby reducing the overall weight of the weapons system. The combination of filler material and sleeve are sufficient to reinforce the barrel following removal of excess diameter material.

Referring to FIGS. 9A through 9C, barrels designed for the M4/AR15 weapons platform as shown. Barrel 14 in FIG. 11A can include varying diameters such as 130 a through 130 g. A front sight with a gas block 132 can be included on the barrel. A gas tube 11 can be received into the front sight gas block and extend rearward away from the muzzle. As can be seen, the gas tube includes a first bend 140 a and a second bend 140 b so that the ends of the gas tube are parallel with the barrel, but the gas tube is able to be positioned so that it is received in the frontsight block and extends over the barrel nut. A handguard cap 134 can be included surrounding the barrel for receiving a handguard. A delta ring 136 can surround the barrel and operability cooperate with the handguard ring to assist with securing a handguard to the barrel. The gas tube can extend away from the muzzle across the barrel nut. Threads 138 can be included in the muzzle end of the barrel for securing items to the barrel such as sound suppressors and flash suppressors.

Referring to FIG. 10, the diameter of the barrel used in one embodiment of the present invention is generally uniform from the muzzle threads to before the barrel extension 142. A shoulder sleeve stop 144 is included in the barrel at a distance 146 from the barrel extension. A first diameter 148 is adjacent to the shoulder stop and adjacent to a second diameter of the barrel 150. The first diameter can taper into the second diameter of the barrel. A barrel gas port 152 is defined in the barrel so that gas from a fired cartridge can escape the barrel before the gas reaches the muzzle.

Referring to FIG. 11A, several components of one embodiment of the invention are shown in an exploded view. A rear sleeve 154 surrounds the barrel creating a rear void 156 between the barrel and the rear sleeve. This rear void can be filled with the filler media described above. The rear sleeve can be attached to a chamber bushing 158 which surrounds the barrel around the first diameter and abuts the shoulder sleeve stop. The chamber bushing and rear sleeve can be press fit, welded, glued, or otherwise secured to each other.

A gas elbow 160 includes smaller diameters at each end so that the rear portion 162 can be received into the rear sleeve. A front portion 164 also has a smaller diameter than the middle portion to be received in a front sleeve 166. The front sleeve and barrel define a front void 168 which can be filled with the filler material described above. End cap 61 can be attached to the front sleeve on one embodiment allowing the threads of the barrel to extend out of the end cap allowing a sound or flash suppressor to be attached to the muzzle end of the barrel. The gas elbow can include a gas block 21 that is in fluid communication with the barrel gas port so that gas escaping the barrel is transferred into a gas channel 168 defined in the gas elbow and can exit the gas elbow through the gas block. The escaping gas can then be redirected toward the action of the weapon platform by the gas tube. In one embodiment, the gas tube is straight without a first or second bend. This allows gas to be transmitted from the gas block to the action without the gas interacting with the bends of a traditional gas tube thereby reducing the movement of the gas tube and the barrel when gas is transmitted through the gas tube.

In one embodiment, an adjustment screw 170 is included in the gas elbow and penetrated into the gas chamber of the gas elbow so that when the adjustment screw extends into the gas chamber, less gas is allowed to enter the gas block. This allows the amount of gas transmitted back toward the action to be varied. When less gas is allowed to travel through the gas tube and ultimately into the cylinder, the force on the rod is varied.

A gas tube retention pin 172 can be included which is inserted into retention pin opening 174 and through the gas tube securing the gas tube into the gas block. A mounting member 176 can be included to be received into a mounting opening 178 and secure the gas elbow to the barrel. In one embodiment, the end cap is replaced with a muzzle brake 60 or sound suppressor and can be attached to the protruding threads of the barrel (FIG. 11B).

Referring to FIG. 12, the gas elbow can include flow channels 180 a through 180 d which provide for fluid communications between the rear void and the front void. In one embodiment, the chamber bushing, rear sleeve, gas elbow, front sleeve are carried by the barrel. The flow channels provide for the rear void and the front void to be in fluid communications. Filler material is placed in the front void and can flow through the flow channels into the rear void.

Referring to FIG. 13, the receiver 12 received the rod that extends from the cylinder. The rod is disposed to travel outside the barrel but so that the barrel does not interfere with the rod's operation. The chamber bushing with the cylinder attached, is disposed at the chamber area of the weapon so that the effect of the impingement associated with the piston and rod on accuracy is reduced. The chamber bushing can be attached to the receiver or can be attached to the barrel. The rod can be received into the existing opening originally made to receive the gas tube of a gas operated weapons system without modification to the receiver. Further, the piston and rod can be of a shorter length than that of the prior art. The piston and rod can float in the cylinder.

Because the rod is received in the existing gas tube opening and the receiver, in one embodiment, 25% or less of the rod is exposed. In one embodiment, between 1% and 50% of the gas tube is exposed. In one embodiment, between 1% and 25% of the gas tube is exposed. By containing the gas tube in the receiving gas tube opening and the cylinder, the ability of the rod to flex due to the operational forces is reduced making the weapon system more accurate and less effected by impingement.

Referring to FIG. 14, the received 12 is shown with the bolt 220 removed. The bolt includes a contact member 222 that contacts the rod which forced the bolt to cycle. Referring to FIG. 15, the existing opening in the receiver for the original gas tube is shown as 224. This allows for the piston system to be installed as a new manufacturing piece or on a existing gas operated weapon as a retrofitted system.

Referring to FIGS. 16A and 16B, one embodiment of the chamber bushing 230 used with a piston system is shown. The chamber bushing includes a first opening 232 and a second opening 234. The first opening receives the sleeve or rear sleeve which encircles the inner barrel. The second opening can receive a cylinder that, in turn, can receive the rod. In one embodiment, the cylinder is attached to the chamber bushing and projects away from the bushing toward the muzzle and overlaps the rear portion of the sleeve or the rear sleeve.

While a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims. 

What is claimed is:
 1. A weapon system including a barrel, a gas escape opening defined in the barrel, a receiver and a gas tube opening defined in the receiver comprising: a front sleeve surrounding a front portion of the rifle barrel; a rear sleeve surrounding a rear portion of the rifle barrel; a gas elbow support surrounding the rifle barrel disposed between the front sleeve and the rear sleeve wherein the gas elbow redirects gas escaping from the gas escape opening; a cylinder attached to the rear sleeve; a gas tube connected between the gas elbow and the cylinder directing gas from the gas elbow to the cylinder; a piston slidably received in the cylinder so that when gas from the gas tube is directed into the cylinder, the piston moves toward the receiver; and, a rod slidably received in the cylinder and the gas opening in the receiver so that when the piston moves toward the receiver, the rod extends into the receiver and contacts a contact member of a bolt causing the bolt to cycle.
 2. The system of claim 1 including: a void defined between the front sleeve, gas elbow, rear sleeve and the outer surface of the barrel; and, a filler material disposed in the void.
 3. The system of claim 2 wherein the filler material includes material taken from the group consisting of: hydraulic cement, at least 50% by weight of calcium sulfate, 48% of less by weight of portland cement, epoxy, resin, graphite and metal particles.
 4. The system of claim 1 including an adjustment screw in the gas elbow to adjust the amount of gas received in the gas tube from the gas elbow thereby varying the force placed on the piston by the directed gas.
 5. The system of claim 1 including a sizing member received in the cylinder that receives the gas tube to reduce the amount of gas escaping from around the gas tube.
 6. The system of claim 1 including a chamber bushing carried by the barrel and attached to the rear sleeve and cylinder.
 7. The system of claim 1 including a cylinder exhaust port allowing gas directed into the cylinder to exit the cylinder once the piston travels a predetermined distance to prevent overpressure in the cylinder.
 8. A weapon system having an action, chamber area, a barrel, a gas escape opening defined in the barrel, a receiver, a gas tube opening defined in the receiver and a gas elbow for directing gas from the gas escape opening into a gas tube attached to the gas elbow comprising: a rear sleeve surrounding the barrel and disposed at the chamber area; a cylinder attached to the rear sleeve and in fluid communications with the gas tube; a rod received through the cylinder extending into the gas tube opening of the receiver so that when gas is directed into the cylinder from the gas tube, the rod extends through the cylinder into the receiver and contacts a bolt causing the bolt to cycle while preventing gas from entering the action.
 9. The system of claim 8 including: a void defined between the barrel and the rear sleeve; and, filler material disposed in the void.
 10. The system of claim 8 including a cylinder exhaust port allowing gas directed into the cylinder to exit the cylinder once the rod travels a predetermined distance to prevent overpressure in the cylinder.
 11. The system of claim 8 including a sizing member disposed between the gas tube and the rod reducing the amount of gas that can escape from around the gas tube.
 12. The system of claim 8 including a piston disposed between the gas tube and the rod so that when gas enters the cylinder, the piston is forced toward the receiver, contacts the rod and forces the rod into the receiver to cycle the bolt.
 13. The system of claim 8 including an adjustment screw in the gas elbow to adjust the amount of gas received in the gas tube from the gas elbow thereby varying the force placed on the piston by the directed gas.
 14. A weapon system having a barrel, a gas escape opening defined in the barrel, a receiver, a gas tube opening defined in the receiver and a gas elbow for directing gas from the gas escape opening into a gas tube attached to the gas elbow comprising: a rear sleeve surrounding a rear portion of the barrel; a cylinder carried by the rear sleeve having a cylinder opening aligned with the gash tube opening of the receiver; a rod slidably received in the cylinder that extends outward from the cylinder and into the gas tube opening of the receiver; and, a gas tube in fluid contact with the cylinder to direct gas from the gas elbow into the cylinder so that the rod is forced in to the received to contact a contact member of a bolt to cycle the bolt when the weapon system is fired.
 15. The system of claim 14 wherein 25% or less of the rod is exposed outside the cylinder or receiver to reduce the rod flexing during operation.
 16. The system of claim 14 including a piston disposed in the cylinder between the gas tube and the rod.
 17. The system of claim 16 wherein the piston floats in the cylinder between the rod and the gas tube.
 18. The system of claim 14 including a sizing member received by the cylinder to reduce the escape of gas from around the gas tube.
 19. The system of claim 14 including: a rear void defined between the barrel and the rear sleeve; and, filler material disposed in the rear void.
 20. The system of claim 19 including: a front sleeve surrounding a front portion of the barrel; a front void defined by the front sleeve and the front potion of the barrel; and, flow channels included in the gas elbow allowing the rear void to be in fluid communications with the front void. 